If z is an odd integer, is 300z 1500?

Question

If z is an odd integer, is 300z > 1500?

(1)  0<\sqrt{z}<8 
(2)  1<z^2<45

ENGRTOMBA2018 · Accepted Answer

Z= odd integer, is 300z>1500 ---> z>5 ? Statement 1, 0 < \sqrt{z} < 8 ---> 1 only possible values are z=3 or 5, giving you a "no" . Sufficient. B is the correct answer.

jmikery · Answer

300z>1500 is just z>5

Using statement 1, we know that Z is the square of either 1, 3, 5, or 7. Meaning Z can be 1, 9, 25, or 49. Since 1<5 while all the others are >5, INSUFFICIENT.

Using statement 2, we know that Z is the square root of either 9 or 25. Z can then be positive or negative 3 or 5. No matter what the sign, all values of Z are not greater than 5, SUFFICIENT

Temurkhon · Answer

z>5? Yes/No St1. 0z>-3*sqrt5. In both case z=<5. SUFF B

AK125 · Answer

Please correct if wrong!! z > 5? 1) 0 < z < 64 --> not clear weather z is bigger than 5. #insufficient 2) 1 < z < 6.7 --> possible number 5 and 3, which means that z is not > 5! #sufficient B)

rocko911 · Answer

Why don't we consider z= -3? the square of -3 will be 3 and its an odd number also (i.e -3)

Bunuel · Answer

The question asks whether z > 5?

From (2)  1<z^2<45  (and the fact that we know that z is odd) it follow that z can be -5, -3, 3, and 5. For each of these values we have a NO answer to the question: z is NOT greater than 5. Sufficient.

Hope it's clear.

aveek86 · Answer

z is an odd integer - but where it is mentioned that 'z' is +ve?
z can be negative, so 'B' is eliminated from the option.
But if 'A' is true then 'z' has to be +ve.

So the right answer will be 'C'.

goalMBA1990 · Answer

Hi, 
This is what I did. But I don't know where I missed. Please correct me.

Statement 1: Given z= odd integer and 0<sqrt(Z)<8. So only possible value of Z is 1 and 300*1=300 is not greater than 1500. Answer is definitely NO. So sufficient.

Statement 2: Z= 3,5 and answer from this statement is also definite NO. So sufficient.

That is why I got D.

Thanks.

Bunuel · Answer

(1)  0 < \sqrt{z} < 8  --> square:  0 < z < 64 . Any odd z will work here: 1, 3, 5, 7, 9, ..., 63. z's less than or equal to 5, give NO answer while greater than 5, give an YES answer. Not sufficient.

goalMBA1990 · Answer

Hi Bunuel,

I agree if I square both sides I will 0 to 64 values for Z not including 0 and 64.

But what is wrong with my method. Suppose I don't square both side and keep statement intact. I mean we are given that Z= odd integer and square root of Z is between 0 and 8. So I can selected Z=1 and square root Z is 1 which between 0 and Z. 300(1) is not greater than 1500. So statement alone is sufficient to answer.

Bunuel · Answer

But you can select many other values for z. Why not 3, 5, 7, ... ? Different z's give different answers.

niks18 · Answer

Hi aveek86 as per the question we need to find 300z>1500 or z>5 (dividing both sides by 300) As per statement 1 0

goalMBA1990 · Answer

Got your point. I was restricting my self for some values only and not understanding the question.

Thanks for clarification.

rekhabishop · Answer

300*5 =1500, and 1500 is not greater than 1500.

Had the question asked, is 300z greater than equal to 1500, the answer would have been B. In this case, there is ambiguity and hence both the statements are insufficient.

zhanbo · Answer

A good question that looks innocent but is tricky enough to have me choose E! That is not a really good start of a new year.

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If z is an odd integer, is 300z > 1500?

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If z is an odd integer, is 300z > 1500?

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